GB417986A - Improvements in and relating to electric lamps - Google Patents

Improvements in and relating to electric lamps

Info

Publication number
GB417986A
GB417986A GB14176/34A GB1417634A GB417986A GB 417986 A GB417986 A GB 417986A GB 14176/34 A GB14176/34 A GB 14176/34A GB 1417634 A GB1417634 A GB 1417634A GB 417986 A GB417986 A GB 417986A
Authority
GB
United Kingdom
Prior art keywords
lamp
filament
cover glass
filaments
light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB14176/34A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
British Thomson Houston Co Ltd
Original Assignee
British Thomson Houston Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by British Thomson Houston Co Ltd filed Critical British Thomson Houston Co Ltd
Publication of GB417986A publication Critical patent/GB417986A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K9/00—Lamps having two or more incandescent bodies separately heated
    • H01K9/02—Lamps having two or more incandescent bodies separately heated to provide substitution in the event of failure of one of the bodies
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/26—Screens; Filters

Landscapes

  • Illuminated Signs And Luminous Advertising (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)

Abstract

417,986. Electric incandescent lamps. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. May 10, 1934, No. 14176. Convention date, May 11, 1933. [Class 39 (ii).] In an electric signal light particularly a traffic control light employing a lamp, a reflector and a lens or cover glass, the lamp has a number of filaments connected in parallel and an indicator screen on the lamp co-operates with one of the filaments to produce light and dark areas on the lens or cover glass upon failure of another filament. The Figure shows a lamp having a main filament 12 and a second filament 13 designed for a longer life than the first and arranged to co-operate with a band of opaque paint 23 wholly or partially surrounding the lamp to produce a shadow on the cover glass when the main filament fails while maintaining a light. Separate or common leading - in wires 14, 22 may be used for the filaments, the second of which is preferably coiled and the other serrated or not. In a modification, opaque stripes are painted on opposite sides of the lamp inclined to or parallel with the axis.
GB14176/34A 1933-05-11 1934-05-10 Improvements in and relating to electric lamps Expired GB417986A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US670448A US2060637A (en) 1933-05-11 1933-05-11 Signal lamp

Publications (1)

Publication Number Publication Date
GB417986A true GB417986A (en) 1934-10-16

Family

ID=24690437

Family Applications (1)

Application Number Title Priority Date Filing Date
GB14176/34A Expired GB417986A (en) 1933-05-11 1934-05-10 Improvements in and relating to electric lamps

Country Status (3)

Country Link
US (1) US2060637A (en)
FR (1) FR773117A (en)
GB (1) GB417986A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2170040A (en) * 1985-01-23 1986-07-23 Walter Anderson Improved light bulbs

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3074013A (en) * 1958-09-23 1963-01-15 Roy N Bowden Device for indicating short circuits

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2170040A (en) * 1985-01-23 1986-07-23 Walter Anderson Improved light bulbs

Also Published As

Publication number Publication date
US2060637A (en) 1936-11-10
FR773117A (en) 1934-11-12

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